Manufacture of oxygenated organic compounds



- acetaldehyde and Febrl, 194 i MANUFACTURE OF OXYGENATED ORGANIC COMPOUNDS Henry Dreyfus, London,

Celan tion of Delaware ese Corporation England, assignor to f America, a corpora- No Drawing. Application March 11, 1941, Serial In Great Britain March 21,

llClalms. (c1.- 260 601 This invention relates to the'manufacture of oxygenated organic compounds more particu-v larly by the utilisation of halogenated olefi e compounds.

According'to the invention, useful oxygenated organic compounds, and especially allphatic'alehydes, oleflne oxides or ketones are produced by subjectinghalogen derivatives of oleflnes to the action of a heating bath containing zinc oxide dispersed, i. e. dissolved or suspended, therein. I

A most important embodiment of the invention isin the treatment of ethylene chlorhydrin and ethylene chloride for the manufacture of ethylene oxide but the invention includes also the treatment of the chlorhydrins, the chlorides and other halogen derivatives of propylene, butylene and other olefines to produce aldehydes, olefine oxides or ketones.

The process is one which does not need the presence of water in ical changes which take place but, nevertheless, it has been found that the presence of a small quantity of water, for instance aquantity equal to about one molecule for each molecule of the halogen compound used as starting material, has a very beneficial effect on the process, especially as regards the yield of desired product. Even smaller quantities of water influence favourably the course of the reactions involved inthe proc ess, for instance quantities down to 002-0.05 molecules for each molecule of halogen compounds but, in general, it is desirable to use a quantity equal to one molecule for each molecule of halogen compound-and larger quantities.e. g. up to four or five or more molecules for each molecule of halogen compound can be used if desired. Thus, the production of ethylene chlorhydrin usually leads to the formation of a prod not containing somewhat less than 10% of ethylene chlorhydrin in aqueous solution and the concentration of this solution canbe doubled by a simple distillation practically the whole of the chlorhydrin passing over during distillation of the first half of the solution. This more-concentratedsolution or the'v'apours producedin such a distillation'can be used immediately for the process of the present invention.

Very satisfactory results have been obtained by using as the heating bath zinc chloridev containing a little water e. g. 4. or or somewhat more, for instance up to 15% and containing also some dissolved or suspended zinc oxide. Such a mixture, which can be kept molten at temperatures in the neighbourhood of 200-250 order to satisfy the chem- C. is very active in the process of the present invention at these temperatures. Higher temperatures can, however, be employed if desired,

e. g. up to 400 C. or even higher, while even at lower temperatures, e. g. down to 150 0., conversion of the halogen derivatives of olefines into the desired 'productstakes place. It is to be notedthat the quantity of zinc oxide present should. be kept well below a quantity equal molecularly to the zinc chloride, so as to avoid the danger of solidification of the zinc oxide and zinc chloride by formation of the cement-like zinc oxychloride. In general a quantity of zinc oxide equal to about 20 to 25% of the weight of the zinc chloride present is most satisfactory although somewhat more zincoxide can be used if desired. During the process zinc oxide present initiallyis transformed into additional zinc chloride. According to the preferred form of the invention, therefore, zinc chloride is continuously or from time to time withdrawn from the vessel containing it, part of the zinc chloride is enriched in zincoxide and returned to the reaction vessel, the excess zinc chloride preferably being subjected to reaction with oxygen to regenerate zinc oxide and chlorine for further use in the process. It is preferred to operate such a process so that at no time does the amount of Y zinc oxide present in the bath fall below-about 10% on the weight of the zinc chloride.

Under such conditions ethylene chlorhydrin and ethylene chloride can be transformed into acetaldehyde with high yields and conversion, sometimes together with ethylene oxide, unchanged starting material or condensable by: products being separated from the substances issuing from' the zinc chloride bycooling and re turned to the process in admixture with a fresh supply of starting materials.

Besides zinc chloride, other inorganic compounds may be used as the basis of the bath in which the zinc oxide is dispersed, compounds having a strong dehydrating action, whether this dehydrating action is exerted physically, chemically or catalytically being especially suitable.

Such substances are, for example, acid, phos-,

' ticular salt employed does not melt at the temperature it-isdesired to employ, mixtures may be employed with more easily fusible substances. It is usually possible, however, by employing an exceedingly concentrated aqueous solution to scrubbing with water.

produce a mixture which it is possible to maintain at the desired reaction temperature in a fused or fluid state.

The starting material may be preheated to the temperature 01' the heating bath or evento a temperature above this before being brought into contact with the catalyst; where relatively high temperatures are used in the process it is undesirable to heat the starting material to a tem perature above that of the heating bath and, if

desired, the preheating temperatures may be somewhat below this, e. g. 5080 C. below.

It is preferred to carry out the process at a pressure not substantially in-excess oi atmospheric pressure and if desired reduced pressure may be used. Thus, the process inthe reaction acne may be maintained from Vs-Vs of an atmos- 3. Process for the controlled oxidation or halogen addition derivatives oi! oleflnes, which comprises passing said derivatives, in vaporous form, through a hot fluid bath heated to 150 to 400 C. and comprising zinc chloride and 20 to 25% of its weight of zinc oxide.

4. Process for the controlled oxidation halogen addition derivatives of oleflnes, which comprises-passing through a hot fluid bath heated to phere or even lower. e. g. down to A0 or A of an atmosphere.

The products should be removed from the re action zone as soon as possible, and this object can best be achievedby employing a rapid stream of starting material; it is. preferred also to arrange for rapid cooling of the products leaving the heating bath. If desired, diluent gases may be employed in admixture with the starting ma-- terials, and such-diluents assist very considerably in removing the products from the heating bath as they are produced.

Nitrogen, carbon dioxide and hydrogen are suitable diluents, and may be present in quite large proportions, equal, for instance, to 4 or 5 or even more, e. g. times the volume of the" vapour oi! the starting material.

The following example illustratesfthe in'vention as applied to the, treatment of ethylene chlorhydrin. Example A mixture is prepared irom zinc chloride and of its weight of zinc oxide and 5-7% of cooled to a temperature of 50-60 C. the liquid condensate being returned to the process, this condensation being effected, if desired, by refluxing. Acetaldehyde is then recovered from the un'co'n'de'nsed products by stronger cooling and/or 150 to see C. andcomprising'zinc chloride, 20 to 25% of its weight of zinc oxide and 4 to 15% of water, a vaporous halogen addition derivative 0! an olefine in admixture with sumcient water-to maintain the water content or said fluid bath.

5. Process for the controlled oxidation of halogen addition derivatives of close, which comprises passing oleflne chlorhydrins, in vaporous form, through a hot fluid bath comprising a major proportion of zinc chloride and a minor proportion of zinc oxide.

6. Process for the controlled oxidation of halo- I gen addition derivatives of oleflnes, which comprises passing through a hot fluid bath. heated to Y 150 to 400 C; and comprising zinc chloride, 20 to 25% of its weight of zinc oxide and 4 to 15% or water, a vaporous oleflne chlorhydrin in admixture with suflicient water to maintain the water content of said fluid bath.

'7. Process for the controlled oxidation of halogen addition derivatives. of oleflnes, which comprises passing ethylene chlorhydrin, in vaporous form, through a hot fluid bath comprising a major proportion of zinc chloride and a minor proportion of zinc oxide.

, 8. Process for the controlled oxidation of halogenaddition derivatives-0i olefines, which comprises passing through a hot fluid bath heated to 150 to 400 C. and comprising zinc chloride, 20

to 25% of its weight of zinc oxide and 4 to 15% of water, vaporous ethylene chlorhydrin inadmixture with sufllcient water to maintain the water content of said fluid bath.

9. Process for the controlled oxidation of halogen addition derlvatives of olefines, which comrises passing propylene chlorhydrin, in vaporous form, through a hot fluid bath comprising a major proportion of zinc chloride and a minor proportion of zinc oxide.

10. Process for the controlled oxidation of halogen addition derivatives of oleflnes, which comprises passing through a hot fluid bath heated to .150 to 400 C. and comprising zinc chloride, 20 to 25% of its weight oi zinc oxide and 4 to 15% Having described myinvention, what I desire to secure by Letters Patent is; v 1. Process for the controlled oxidation of halogen addition derivatives of oleflnes, which comprises passing said derivatives through a hot fluid bath comprising a major proportion of zinc chloride and a minor proportion of zinc oxide.

2. Process for the controlled oxidation of halogen addition derivatives of oleflnes, which comprises passing said derivatives, in vaporous form, through a hot fluid bath comprising a major proportion of zinc chloride and a minor proportion of zinc oxide.

of water, vaporous propylene chlorhydrin in admixture with suflicient water tomaintain the water content or said fluid bath.

11. Process for the preparation of acetaldehyde by the controlled oxidation of ethylene chlorhydrin, which comprises passing through a hot fluid bath heated to 250 to 255. C. and comprising zinc chloride, 20% of its weight of zincoxide and 5 to 7% of water, vaporous ethylene chlorhydrin in admixture with sufficientv water vapor to maintain the water content of said fluid bath, and recovering acetaldehyde from the vapors issuing from the reaction zone.

HENRY Dams; 

